Catalytic Combustion of Diesel Soot over Ce0.5+xZr0.4-xLa0.1O2-Al2O3 Catalysts

Ce0.5+xZr0.4-xLa0.1O2-Al2O3 catalysts were prepared by co-precipitation, where 0 <= x <= 0.4 and the mass ratio of Ce0.5+xZr0.4-xLa0.1O2:Al2O3 was 1:1. The catalytic activities of these catalysts for the catalytic combustion of diesel soot were investigated. The catalysts were further characterized by low temperature nitrogen adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H-2-temperature-programmed reduction (H-2-TPR), and O-2-temperature-programmed desorption (O-2-TPD). The results showed that all the catalysts formed solid solutions with a fluorite-like structure. When x=0.2, the Ce3+ ions were partly rich on the surface of the catalyst. The catalyst was easily reduced by H-2 and the desorption peak area of the beta oxygen species was the largest. The light-off temperature was 360 degrees C for the catalytic combustion of diesel soot over the catalyst suggesting good catalytic activity and potential application in diesel soot catalytic combustion.